Recently, patient number of adult disease such as diabetes and so forth, which is caused by changing of diet or life style, is increasing, and some means are needed. Here, the adult disease is defined as a concept including many diseases such as diabetes derived from life style, hypertension, hyperlipidemia, pneumonectasia caused by smoking, or the like. Among the adult disease, metabolic disease is defined that visceral fat accumulation type obesity, of which visceral fat area is not less than 100 cm2, and it complicated two indexes among following three: triglyceride level is not lower than 150 mg/dL, or LDL cholesterol level is less than 40 mg/dL), upper level of blood pressure (systolic blood pressure is not lower than 130 mmHg, or diastolic blood pressure is not lower than 85 mmHg), and hyperglycemia (fasting blood sugar is 110 mg/dL). The metabolic syndrome is a comorbid disease more than two of the above three indexes.
It is known that, in relationship between diet and the adult disease, high fat diet induced obesity that causes systemic insulin resistant to develop diabetes, hyperlipidemia, and hypertension. Furthermore, it is also recently clarified that these become risk factors to cause arteriosclerotic cardiovascular disease. Therefore, prophylaxis of insulin resistant and treatment thereof are important.
Here, insulin resistant is defined that “the decrease of insulin action in skeletal muscle, liver, and, adipose tissues as target tissues thereof”. The type 2 diabetes recently becoming popular is defined that “the disease caused by decrease of insulin secretion from n-cells in pancreas, and decrease of insulin action in skeletal muscle, liver, and adipose tissues as target tissues thereof”.
Conventionally, as a treating agents for diabetes, sulfonylurea agents (SU urea agent) such as tolbutamide, gliclazide, glimepiride, and so forth, a fast-acting Insulin secretion booster such as nateglinide, mitiglinide calcium compound and so forth, phenylalanine derivative agents, biguanide drugs such as metformin, buformin and so forth, insulin-sensitizing agent such as pioglitazone, rosiglitazone, and so forth, thiazolidines have been developed and used (see, non-patent document, hereinafter, it is referred to as the “prior art 1”).
Other than such western medicine, the patent publication, JP2000-103742 A, discloses that ethanol extract from several plants including nagaba gishigishi (Rumex crispus), of which root is subjected to be extracted, shows amylase inhibition activities in vitro (see, patent document No. 1, hereinafter, it is referred to as the “prior art 2”). Also, the other patent publication, JP2005-325025 A, discloses that water extracts from 24 kind of crude medicine (crude drug) including kogane gishigishi (R. maritimus), which is belonging to the same species as Nagaba Gishigishi, have blood sugar level decreasing effect for rat with alloxan-induced diabetes (see, patent document 2, hereinafter, it is referred to as the “prior art 3”).